This invention relates to motorized vehicles and more particularly to a monitor system which indicates the presence of undesirable conditions in the engine or other vehicle components.
In motorized vehicles of virtually all kinds, instruments are employed to detect the presence of various undesirable operating conditions such as overheating of the engine, low oil pressure, low fuel and the like, and indicators are provided to give warning to the vehicle operator of such condition. In some vehicles similar instruments and indicators are provided to indicate operating faults distinct from the engine. In earthmoving vehicles for example, when the engine operates a pump to supply pressurized fluid to hydraulic cylinders for manipulating elements of the vehicle, instruments may be present to indicate a low level of hydraulic fluid in the supply reservoir, an overheating of the hydraulic fluid, a clogging of the hydraulic fluid filter and so on.
The importance of the various monitored conditions varies, both as to criticality and as to time in relation to the operation of the vehicle. For example, the levels of the various fluids such as engine oil, transmission fluid, hydraulic fluid and coolant fluid should be checked and deficiencies corrected prior to start-up of the vehicle. Operating conditions such as brake pressure, coolant temperature, fuel level, whether the parking brake is on and the like should be monitored prior to and during the time the vehicle is in operation. Some operating conditions are more critical than others, insofar as the need for immediate action on the part of the operator is required. The existence of a low alternator output would be an example of a relatively noncritical condition. The operator should be warned of such condition, but no immediate corrective action would be needed. On the other hand, a loss of brake pressure would require the operator to take immediate steps to prevent damage to the vehicle. Other conditions may arise and be detectable when the vehicle is in operation, such conditions indicating a need for servicing the vehicle when it is returned to the shop. For example, the oil filter may clog during vehicle operation and need cleaning or replacement when the vehicle is through for the day.
Heretofore, monitor systems have detected the undesired conditions and then signaled the vehicle operator by means of dial indicators, indicator lamps or audible means. The efficiency of these systems is greatly dependent upon the operator's careful attention to all of the various indicators and upon his judgment as to which may call for immediate correction and which may be deferred. In general, the more complex the vehicle and its auxiliary equipment, the greater is the number of operating conditions that should be monitored. At the same time, the more complex the vehicle, the less the time the operator will have to observe the greater number of various indicators since he will be more immediately concerned with direct vehicle operation.
Thus, with an increasing amount of instrumentation, a definite problem exists as to how the existence of undesirable conditions can be detected and presented to the operator without a need on his part to give greater attention, which he does not have, to such instrumentation and make more value judgments relative to the existence of undesirable conditions.